1. Field of the Invention
The present invention relates to a spring seat fixing structure for a hydraulic shock absorber.
2. Description of the Related Art
Conventionally, a hydraulic shock absorber having a damper tube and a suspension spring has been proposed as disclosed in Examined Utility Model Publication (Kokoku) No. 55-12608. The hydraulic shock absorber is constructed in a manner that a cap is fixedly forced (pressed in) into a periphery of a shaft seal part of the damper tube, and a spring seat for the suspension spring is located on an outer periphery on a distal end side of the cap.
In the aforesaid hydraulic shock absorber, in the case of providing a suspension spring having a desired length along an axial direction around the damper tube, a spring seat for the suspension spring must be located on a distal end side separated from the shaft seal part of the damper tube in the axial direction. Further, in order to retain the spring seat onto the damper tube without a misalignment, it is preferable that the cap is fixedly forced into the damper tube up to a location nearest to a spring seat mounting portion on the distal end side of the cap. Therefore, the cap needs to be fixedly forced into the damper tube by a considerably long range up to a location nearest to the spring seat mounting portion considerably separated from the shaft seal part of the damper tube in the axial direction.
However, in the aforesaid prior art, an outer diameter of the damper tube is formed in a straight line. In the case where a considerably long portion from a proximal end side to the distal end side of the cap is used as a force-fit portion, in a process for fixedly forcing a force-fit portion on the distal end side of the cap into an outer diameter portion of the damper tube, a long portion of the damper tube is used as a force-fit surface. For this reason, it is difficult to force the cap into the damper tube.